Coal-fired burners are commonly used to make steam in, for example, electrical generating plants. The burner structure includes a large enclosure with pre-aimed nozzles mounted at four diagonally-spaced locations. As schematically shown in FIG. 6A of the attached drawings, the nozzles direct streams of pulverized coal toward tangent points on an imaginary circle representing a fireball substantially at the center of the enclosure. Although the nozzles may include a capacity for tilting to raise or lower the fireball in the enclosure, there is no provision for adjusting lateral aim; therefore, the degree of tangentiality in the aiming of all four nozzles remains fixed after installation for all practical purposes.